Hydrostatic transaxle units are popular with both the manufacturers and consumer users of riding mowers and lawn and garden tractors (tractors). This type of tractor is typified by a vertical shaft engine and a primary emphasis on mowing duties. The tractors normally are not suited for use with heavy ground engaging implements or for high percentage duty cycles. With hydrostatic transaxles in such units, the manufacturer gets a complete all-in-one transaxle needing only a belt to the engine and a control lever to form the entire ground engaging propulsion power unit for the tractor. The consumer gets a relatively simple to use and easy to understand single control for the speed and direction of the tractor. However, hydrostatic transaxles are not perfect. Major limitations to their use include their internal complexity and resultant increased costs (i.e. incorporating both a hydraulic power pack and gears), their size (i.e. both the hydraulic power pack and gears need a certain set space each) and their lack of ease in exchangeability with purely mechanical power units (i.e. different frame design). These limitations restrict the applications and market place acceptance for hydrostatic transaxles.
The present invention is directed towards providing a simple, inexpensive, small, and strong hydrostatic transaxle.